Method of forming a fiber, a fiber, and an article comprising one or more strands of fibers

Abstract

There is provided a method of forming a fiber, the method comprising preparing a dope comprising a metal ion coordination polymer; and forming a precursor fiber from the dope in air, wherein the precursor fiber undergoes a phase transition from a liquid or semi-liquid state to the fiber in a solid state in air. There is also provided a fiber comprising a metal ion coordination polymer, said metal ion coordination polymer comprising, a plurality of metal ions acting as nodes; and a plurality of organic ligands acting as linkers, wherein the metal ions are linked to the organic ligands via coordination bonds to form a network structure of the metal ion coordination polymer. There is further provided an article comprising one or more strands of fibers formed by the method as disclosed herein, or one or more strands of fibers as disclosed herein.

1 . A method of forming a fiber, the method comprising
 preparing a dope comprising a metal ion coordination polymer; and   forming a precursor fiber from the dope in air,   wherein the precursor fiber undergoes a phase transition from a liquid or semi-liquid state to the fiber in a solid state in air.   
     
     
         2 . The method according to  claim 1 , wherein preparing the dope comprises dissolving a polymer resin and a metal ion source in a solvent to obtain a solution of the polymer resin and the metal ion source. 
     
     
         3 . The method according to  claim 2 , wherein preparing the dope further comprises curing the solution of the polymer resin and the metal ion source to obtain the dope comprising the metal ion coordination polymer. 
     
     
         4 . The method according to  claim 3 , wherein the solution of the polymer resin and the metal ion source is cured for a duration falling in the range of from 5 hours to 150 hours at a temperature falling in the range of from 20° C. to 90° C. 
     
     
         5 . The method according to  claim 3 , wherein the solution of the polymer resin and the metal ion source is cured until the dope satisfies one or more of the following conditions:
 (i) a viscosity falling in the range of from 10 Pa·s to 50 Pa·s;   (ii) a storage modulus falling in the range of from 100 Pa to 200 Pa; and   (iii) a loss modulus falling in the range of from 10 Pa to 150 Pa.   
     
     
         6 . The method according to  claim 2 , wherein the polymer resin is selected from the group consisting of polyacrylonitrile, poly(methacrylic acid), sodium polyacrylate, acrylonitrile butadiene styrene, and nitrile butadiene rubber. 
     
     
         7 . The method according to  claim 2 , wherein the metal ion is selected from the group consisting of silver, iron, zinc, and bismuth. 
     
     
         8 . The method according to  claim 2 , wherein 5 wt. % to 20 wt. % of the polymer resin is dissolved in the solvent. 
     
     
         9 . The method according to  claim 2 , wherein the metal ion source is provided by dissolving a salt of the metal ion in the solvent. 
     
     
         10 . The method according to  claim 9 , wherein 2 wt. % to 20 wt. % of the salt of the metal ion is dissolved in the solvent. 
     
     
         11 . The method according to  claim 2 , wherein the solvent is selected from the group consisting of dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), a mixture of DMF-water, and a mixture of NMP-water. 
     
     
         12 . The method according to  claim 1 , wherein forming the precursor fiber comprises spinning the precursor fiber from the dope. 
     
     
         13 . The method according to  claim 1 , wherein the precursor fiber is formed from the dope in air having atmospheric pressure, a relative humidity falling in the range of from 40% to 95%, and a temperature falling in the range of from 20° C. to 50° C. 
     
     
         14 . The method according to  claim 1 , wherein the metal ion coordination polymer in the dope comprises,
 a plurality of metal ions acting as nodes; and   a plurality of organic ligands acting as linkers,   wherein the metal ions are linked to the organic ligands via coordination bonds to form a network structure of the metal ion coordination polymer.   
     
     
         15 . The method according to  claim 14 , wherein the metal ion is silver ion and the ligand is a nitrile group; and wherein the silver ions are linked to the nitrile ligands via coordination bonds to form a [Ag(N≡C—) x ] +  complex, wherein x is an integer that is no less than 1 and no more than 3. 
     
     
         16 . A fiber comprising a metal ion coordination polymer, said metal ion coordination polymer comprising,
 a plurality of metal ions acting as nodes; and   a plurality of organic ligands acting as linkers,   wherein the metal ions are linked to the organic ligands via coordination bonds to form a network structure of the metal ion coordination polymer.   
     
     
         17 . The fiber according to  claim 16 , wherein the metal ion is silver ion and the ligand is a nitrile group; and wherein the silver ions are linked to the nitrile ligands via coordination bonds to form a [Ag(N≡C—) x ] +  complex, wherein x is an integer that is no less than 1 and no more than 3. 
     
     
         18 . The fiber according to  claim 16 , further comprising nanoparticles of the metal interspersed in the network structure of the metal ion coordination polymer. 
     
     
         19 . The fiber according to  claim 16 , wherein the fiber has one or more of the following properties:
 an axial strain of at least 500%;   a tensile strength of at least 6 MPa; and   wan electrical conductivity of from 0.1 S/m to 100 S/m.   
     
     
         20 . An article comprising one or more strands of fibers formed by the method as defined in  claim 1 . 
     
     
         21 . An article comprising one or more strands of fibers according to  claim 16 .